Photo-engraver&#39;s cabinet



Dec. 31, 1929. w DOBINSQN 1,741,684

PHOTO ENGRAVERS CABINET Filed Jan. 8, @927 Z a I I I 1 13 4. I 1

45 pear.

Patented Dec. 31, 1929 PATENT OFFICE WILLIAM J. DOBINSON, F SOMERVILLE, MASSACHUSETTS ruo'ro-nnen-avnn s CABINET.

Application filed January 8, 1927. Serial No. 159,938.

' This invention relates to appliances known as blood boxes and blooding cabinets used by photo engravers in preparing partially etched zinc plates for further etching by applying to the partially etched surfaces a dark red East Indian resin, called dragons blood, the resin being finely powdered.

Usually the powder is kept in a shallow box or tray, and the plate is held by the op- 0 erator on one edge of the tray. A fiat brush charged with the powder is then swept across the plate, to cause some of the powder to lodge against the sides of the etched lines, the lodged powder being subsequently melted by heating the plate so that it adheres to the lines and prevents the undercutting of the lines during subsequent etchings. I

During the brushing operation, and particularly while the excess powder is being brushed from the plate into the tray, the

finest particles'of the powder which COIlStl, tute the most valuable portion thereof, are caused by the agitation to rise as dust into the air, and then settle on surfaces in the vicinity, causing annoyance. If the surfaces include those of other partially etched plates in the vicinity, damage well known to photoengravers is caused. The dust-laden'air is liable to. be inhaled by the operator, to his 0 physical detriment, and the loss of material in the form of dust is considerable.

The chief object of my invention is to provide a cabinet in which the operation of ap plying dragons blood to lines of partially etched photo-mechanical .plates may be conveniently performed, and whereby the powder which rises from the plate may be unobjectionably disposed of, by depositing the major portion in the cabinet,so that it may -10 be recovered, and so delivering any unrecoverable residue that it may be conducted away from the cabinet, and discharged at a distant point.

Other related objects will hereinafter ap- Of a part of this specification,-

Figure 1 is a perspective view of a cabi-' the accompanying drawings formingindicated by line 2-2 of Figure 1, showing the plate in the position it occupies when surplus powder is being brushed off, a brush being shown.

Figure 3 is a section on line 3-3 of Figure 2.

Figure 4 is a viewsimilar to a portion of Figure 2, omitting the plate, and showing the hereinafter described rear plate rest displaced.

Figure 5 is a fragmentary section on line 5,5 of Figure 2.

' The same reference characters indicate the same parts in all of the figures.

My improved cabinet is'preferably composed of sheet metal members and suitable re inforcing frame members, forming a vertically elongated cabinet which may be ap proximately five feet high, three feet wide, and two and one-half feet deep from front to back. These proportions are suitable, but of course, may be varied. The vertical front, back and side wallsof the cabinet are designated by the reference numeral 1, the bottom by 1 and the top by 1 The upper portion of the cabinet constitutes a working chamber, which is open at the front side of the cabinet,the front wall being provided with an opening 3 (Figures 2 and 4), permitting free access to the working chamber.

, The lower portion of the cabinet constitutes a settling chamber, in which the surplus powder is deposited, as hereinafter de scribed. The working chamber isconnected,withthe upper portion of the settling chamber at one side of the latter by a vertical flue 5, vpreferably located at the back of the cabinet, one side of the flue being formed, in this instance, by a vertical sheet metal member 6, spaced from the back wall of the cabinet. Said fluejis adapted to conduct floating powder fromthe working chamber to the settling chamber.

Communicating with the settlin chamber, at the front upper portion thereo is an exhaust' outlet, vadapted to be connected with an exhaust conduit section 7, (Figure 5) cabinet and be connected with a suction fan or blower (not shown), whereby an air current may be induced through the working chamber, the passage 5, the settling chamber and the exhaust conduit.

The exhaust outlet is preferably provided by a tube 8, extending horizontally from side to side of the settling chamber, and through the side walls thereof, as shown Figure 5. The conduit section 7 may be connected with either of the projecting ends of the tube 8, the other end being closed by a cap 9. The tube is provided with an intalie opening 10 which is preferably an elongated slot, formed and arranged to widen the portion of the induced current entering the tube 8, so that the width at he c r en is ubs antia ly eq al. i the Width o he ambe -i The a s n-" en nt g t e upp r p rti n. of the. settling chamber at the rear'side thereof, flows t y across the hamber t its f ont i so that time is allowed for powder carried by th Cu te all t the bottom o the. se tling chamber.

Th a ng m n hewn is uch that bl od-- ing powder set free in the working chamber during the operation of applying 'the powder to a partially etched plate 1?, supported in, he r ing chamber, is, d awn by he duced current from the working chamber thr h the x au t ine 5 ts he s t li cham the m jor pert en o the render. is depo ited a 2 n the. bottom of h e arnher, and the air, and any floating pow er. c rried y, re exh ust through the exhaust u let 8 and ondn t 13 designates a baflie plate in the settling chamber, between the exhaust fine, 5 and the exha s utlet 8, whereby th induced eii r i efl ted owa d the bettern of. the set tling chamber, so that said current passes up: Ward to he xha t iit et8, a ter Pas i g under the baffle-plate, This; change in the dire tion o th urr nt f ei tes the d p sh n of p wder on he otto o the s t lin ehani er- The ba he-pla e, p eferab y f sheet metal, extends entirely across the set: tling chamber, between the side walls thereof, and is connected in this instance, with a hori; z n al parti ion 14, xt nding t ain. the eat Wal a th ab net to the fine 5- T eahinet s provide it a fixed trent esale, at he fren of t e Wo k ng ham er, erpen ine th n e p r i n of t e p at a l ng; th brushing eneretien P r-termed by brash Ba Within the working chamber, and suitably spa ed fro the fr nt. s i a e isplaeeab e rea rest. p ei rahly e nstrn ed a here n after d s ribed, s nh tina he nne aer tion of the plate.

The re ts; are; eea ed. ahe e pen vdile- Pinaay 6, een ti-tn ina the ho tern Par ies f t e rking -hanih r,v a apted o non-- t in a supply o bleed ng p wde into W eh the Pla e may be lipped by the pera or, te

- tak up. a s p ly of the near-d an stance, the bottom of the dipping tray is formed by a horizontal partition 16, extending from the front wall of the cabinet to the wall 6 of the exhaust flue 5, and the front rest 15 is formed by a portion of the front wall which projects above the partition 16 and const tut s he fr all of h dipp g tray 16- v t The displaceable rear rest, as here shown, is a swinging U-shaped member composed of a pair of arms 17, having tr-unnions 18, journaled i hearings in the side walls of the cabinet, and a neck 19 constituting the acting portion of the rest, and displaceable rear- 'wardly, as shown by Figure 4, by a swinging movement of th U hape l m mber: The iect of thus di p acing he ear rest i to lea e t e cl pp g tray 16. unob ucted, so tha the pla e P e c enien ly dipped: th r in The .disp ae ahle re t may he leaked in it opera i e an it d splae d. pes tiQns y means in ding; a crank 20, xed to n f. the trunnions 18 and provided with a detent member 2 (F g e h), adapt d to ngage ei her of a ies'e le en n n1hers2 n a side Wall o he abinet,

e in ent tions. ad p ed n g g the member '21- The crank 2 constitutes a m an f r moving the displaceah e r s I. am no l m ted to thi sp ific displa eable rest constructi n- The p r i io n 1 may e paee l apa a erm. the uppe and lower sid s f a. space n which a draw r 3,, cont ining a eser e upply of powder, is sh ahle- Qremtz'aa h supp y of ren er s pla in e dip-ping tray 16; the r r re t. is dis: planed,v a Sha by Figure 4, he su io hle e i starte and the plat P, revio ly par y e ehed,, is dip-peel in the powd r the tray 1 and hen steed up on dge o allow the powder taken up by the p ate o set le pon. he upper s des of the line o e pla Th d plaeeahle e i n s ea ed; it operativ position, hawnhy Figure. 2, and the plate is denesited n th w rests Th brush B, is then moved over the upper side of he plate, to; thre the p er mo osey again the lin s o the P ate andv rem ve the surplus powder from the plate. The loose pew-den hus set. i when d a n by the nd ce airnrrent th engh th exhaus flii nto the. se tling ehaniher which he Sp ed ef t e dust-la en is r -n eda he air cu re t xpandsin th se tling chamber, nd Passe un er the a ent T pow e r in den maj r per i n is deposited at 12, for subsequent removal through hand heles ha ing re ne v hle elio ii s. 2. (Figu 1). The air and any residuum of dust car? ried the eby then r e and is, d awn, th ough the exhaust outlet 8, and conduit. section 7, he di eh raed at any suita y d s nt p i TO enable the eieerat r o, c n eniently sheet. the plate B, n the w rking chambe The members 22 the plate rests.

I provide the top 1 of the cabinet with a recess 25. Electric lamps 26 may be located in the upper portion of the working chamber, to illuminate the plate. I

The dipping tray 16 is located below the front opening 3, and forms the bottom of the Working chamber. The outer plate rest 15 constitutes the outer end of the tray and is located above the bottom of the tray and at the lower end of the front opening. The intake end of the exhaust passage 5 communicates with the working chamber above The relative arrangement of the dipping tray, the front opening, the plate rests, and the intake end of the exhaust passage is therefore such that the dipping tray is located below an air current flowing through the front opening to the exhaust passage, while the plate rests are located withr in said current, so that powder in the tray is unaffected by the current, while the liner portion of the powder rising from a plate supported by the rests is carried away by the current, the heavier portion, which is the major portion of the powder, settling in the tray.

I claim:

1. A cabinet of the character stated comprising in combination a working chamber, having a front opening, a settling chamber below the working chamber closed at its lower portion, a vertical exhaust flue adapted to conduct floating powder. downward from the working chamber to one side of the upper portion of the settling chamber, an exhaust outlet communicating with the opposite ends of the upper portion of the settling chamber, and adapted to be connected with suction means whereby an air current may be induced through the working chamber, the exhaust flue and across the settling chamber to the exhaust outlet. and a baflie plate extending from the top partly to the bottom of the settling chamber between the exhaust flue and the exhaust outlet, the arrangement being such that blooding powder set free in the working chamber during the operation of lengthwise of the tube and elongated to widen the portion of the induced current entering the tube.

3. cabinet comprising a working chamber having a front opening, a dipping tray located below said opening, the bottom of said tray forming the bottom of the working chamber, an outer plate rest located above the outer end of the tray bottom, and at the lower ed with suction means whereby an air current may be induced through the working chamber, the exhaust flue and the settling chamber, the arrangement being such that the dipping tray is located below and the plate rests within, an air current flowing through the front opening to the exhaust flue, so that powder in the tray is unaffected by said current, while powder set free from a plate supported by the rests is carried away .by the air current.

4. A cabinet as specified by claim 3, the inner plate rest being movable and displaceable, to permit an unobstructed dipping of a plate in the tray.

In testimony whereof I have affixed my signature. r

WILLIAM J. DOBINSON.

blooding a partially etched plate, is drawn by the induced current from the working chamber through the exhaust flue to the settling chamber, the major portion of the powder isdeposited on the bottom of said chamber under the baflle plate, and the air and any residuum of floating powder carried thereby are exhausted through said outlet, the baffle plate facilitating the deposition of powder onthe bottom of the settling chamber.

2. A cabinet as specified by claim 1, the

, exhaust outlet being a substantially horizontal tube extending across the settling chamber at one side of the upper portion thereof, adapted to be connected with a conduit section outside the chamber, and provided within the chamber with a substantially horizontal intake slot, extending 

